www.hhmi.org >> resources & publications >> students >> biointeractive >> virtual labs > "The Bacterial Identification Lab"
The procedures necessary for extracting and isolating DNA of an unknown bacteria are costly, time consuming, and can even be dangerous in that it can expose a lab technician to pathogens. Fortunately, technology has given us virtual labs that will show how these procedures are done without the mess and the fuss. In this internet activity, you will use a virtual lab to perform the following procedures:
1. The first step in the extraction process uses a wire loop to do what?
2. Why are the digestive enzymes necessary for DNA extraction?
3. The centrifuge separates the cellular content into two distinct layers. Describe these layers and what is contained within them.
4. PCR stands for ___________________________________
5. What is a primer?
6. Describe what happens during the 3 cycles
7. After 30 cycles, how many copies of the initial DNA strand have been produced?
Why is this stage called "amplification"?
8. To confirm that the PCR worked, three lanes are run that contain 3 materials. What materials are in the 3 lanes?
Lane 1 _______________________ Lane 2 ____________________ Lane 3 _______________________
9. What is the overall purpose of the purification stage?
10. Describe the sequencing brew that you added your purified PCR to.
11. The purpose of the second PCR is not to create identical copies like the first PCR you ran. What is the purpose of this PCR?
12. What is the final PCR product, the stuff contained in your 12 tubes?
13. What is gel electrophoresis?
14. What is BLAST?
15. What is the identity of the bacteria in your sample? Follow the steps listed on the page and be patient. BLAST data can take a while to search.
Extension and Formative Assessment
**Look at the learning objectives at the beginning of this sheet. Did you accomplish these objectives? Redo the simulation to reinforce the steps involved. Write a short essay that discusses the learning objectives in this lab to show that you have accomplished them.**